Sound cue pitch does not modulate on Android

I’m buillding a bubble-popping game. I have built a simple sound cue that plays a popping sound with two sources of modulation:

  1. The bigger the bubble, the lower the
  2. The default Modulator which
    adds +/- 5% random modulation

When playing on desktop, this works fine. However, when packaging and running on an Android target device, the pitch of the pop sound is constant.

The same thing happens whether a build, sign, and install for distribution, or just Launch a level preview on-device from the toolbar.
I know that the scaling factor is properly calculated, because it’s also used to render the bubbles I’m popping, and those have the right scaling applied.

Using the latest 4.7.5 Unreal Engine, downloaded from launcher.
Testing on Andriod 4.4.4 running on a OnePlus One 64 GB.

Pitch modulation isn’t supported on Android right now - there’s nothing in the code itself to implement it.

I think it has something to do with the way OpenSLES is implemented on Android.

However it would be nice to know if there are plans about this.

Thanks for the answer. That’s… astounding. I did pitch modulation in software on a Pentium II / 300 and it used less than one percent of the CPU. It’s one of the first things anyone will implement in a software sound renderer, because it’s the same thing as sample rate conversion. For this to be missing is … I don’t have words. Maybe I should have gone into liberal arts :-/ It’s like saying “oh, yeah, vertex colors aren’t supported” or something for graphics.

Yeah, you could even say that it’s sad.
Epic is not to be blamed in this particular case, it really is an Android issue.

A workaround could be to create a custom procedural sound node and filling its internal buffer yourself based on the pitch value.
However, the fact that no easy audio callback is available in UE4 makes this sort of requirements a lot harder than they should be to implement.

This is still true today, with version 4.17.2 and Nougat apparently. It’s a shame =(

This is a real shame! It’s just that extra bit difficult to reduce the repetitive nature of some sound effects. It’s really not great that it’s already a struggle to cut down package sizes for android!

Thanks for the concise answer. :slight_smile: